Answer:
[tex]\dfrac{1}{3}(b-21)[/tex]
Step-by-step explanation:
We need to find an equivalent expression for [tex]\dfrac{1}{3}b-7[/tex]
The denominator of first fraction is 3 and that of other is 1.
[tex]\dfrac{1}{3}b-7\\\\=\dfrac{b-21}{3}[/tex]
or
[tex]=\dfrac{1}{3}(b-21)[/tex]
Hence, the equivalent expression is [tex]\dfrac{1}{3}(b-21)[/tex].
